Strain-insulator.



O. L. FLETCHER.

STRAIN INSULATOR.

APPLICATION FILED AUG 16, 1911.

1,028,104. Patented June 4, 1912.

' UNITED sTATEs PATENT OFFICE.

OLIVE L. FLETCHER, OF PERU, INDIANA, ASSIGNOR TO PERU ELEGTRIQCOMPANY, OF PERU, INDIANA, A CORPORATION OF INDIANA.

STRAIN-INSULATOR.

Specification of Letters Patent.

Application filed August 16, 1911. Serial No. 644,432.

Patented June 4., 1912.

To all whom it may concern:

Be it known that I, OLIVE L. FLETCHER, a citizen of the United States, residing at Peru, in the county of Miami and State of Indiana, have invented new and usefulImprovements in Strain-Insulators, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

The purpose of this invention is to provide an improved form of strain insulator for use in connection with electrical wiring.

It consists of the features of construction shown and described in the drawings as indicated in the claims; 7

' In the drawings :--Figure 1 is a medial section of the insulator taken as indicated at line 1-1 on Fig. 2. Fig. 2 is a side elevation of the same. Fig. 3 is an end elevation of the insulator, being a section taken as indicated at line 3-3 onFig. 2.

The drawings illustrate a form of insulator, A, particularly adapted for use where two 'wires, B and C, are connected, one of which is in contact or liable to come in contact with one of the wires of an electric circuit, while the other which serves as a stay or guy wire, is usually secured to a post in the ground so that it becomes necessary to insure insulation of the one from the other to prevent grounding the circuit. Each of the wires, B and C, terminates in a loop, and these loops are linked together but spaced apart'by means of the insulator, A, to avoid contact with each.

other.

The insulator is provided with a pair of similar guide ways lying in planes at right angles to each other to secure the greatest obtainable spacing of the two 100 s. Each guide way co sis ts of a pair 0 parallel grooves, A fgrmed in opposite sides of the outer sur ace of the insulator body and connected by a third groove, A extending throu h the insulator. The bottom portion 0 the groove, A is substantially cylindrical and of sufficient size to easily accommodate the wire, B or C, as the case may be; but at its up er or opening portion, A, the width of t e grooveis reduced to something less than the diameter of the wire for which it is intended. The purpose of this construction is to prevent the loop of either wire from coming out of the groove, A into contact with the other loop, if at any time the tension in the Wires is slackened. In this way, the danger to linemen which has heretofore been present in adjusting or replacing guy wires is greatly reduced, and convenience of handli g is increased, since the loops remain in glace on the insulator even when all tensio is removed from the wires. This result it may be understood, might be accomplished by leaving the arrow portion, A of each groove completely closed, thus rendering the portion, A, an aperture merely. But, when this is donethere is considerable liability in cpld weather that the aperture, A will become filled with.

sleet or snow and water so that upon the formation of a solid block of ice in the aperture, the expansion'which is character-- istic of water in the process of freezing will frequently operate to burst the insulator or at least to crack it, so as to render it unsafe for the proper performance of its function. The provision of the opening, A, permits this expansion to take place without injury to the insulator, and thus renders it practicable for use in all climates and under all conditions.

I claim 1. A strain insulator comprising a body of insulating material having a groove formed in its surface and adapted to receive a wire looped around the insulator, the bottom portion of said groove being wider than the wire which it -is intended to receive, and the top or opening portion of the groove being narrower than such wire. v

2. A strain insulator comprising a bod of insulating material provided with two parallel grooves formed in opposite sides of the body and connected by a transverse groove at one end, said transverse groove being wider toward the bottom than the strain wire which it is designed to accommodate and being narrower than-such wire in its upper or opening portion.

3. A strain insulator comprising a body of insulating material provided with twotestimony whereof I have hereunto I grooves formed in the surface of said body set my hand at the city. of Peru, Miami and lying in directly transverse planes, recounty, Indiana,v this 12 day of August, 1911. 10 spectively, a. portion of each groove belng OLIVE L. FLETCHER. wider at the bottom than the wire which Witnesses:

it is desi ed to accommodate, and narrower WALTER C. BAILEY,-

than sai wire near the top of the groove. G Y R. YORK. 

